Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C2/00—Rotary-piston machines or pumps
  • F04C2/08—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
  • F04C2/082—Details specially related to intermeshing engagement type machines or pumps
  • F04C2/086—Carter
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C14/00—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations
  • F04C14/24—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by using valves controlling pressure or flow rate, e.g. discharge valves or unloading valves
  • F04C14/26—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by using valves controlling pressure or flow rate, e.g. discharge valves or unloading valves using bypass channels
  • F04C14/265—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by using valves controlling pressure or flow rate, e.g. discharge valves or unloading valves using bypass channels being obtained by displacing a lateral sealing face
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C2/00—Rotary-piston machines or pumps
  • F04C2/08—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
  • F04C2/12—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type
  • F04C2/14—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C2240/00—Components
  • F04C2240/50—Bearings
  • F04C2240/51—Bearings for cantilever assemblies
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C2270/00—Control; Monitoring or safety arrangements
  • F04C2270/17—Tolerance; Play; Gap

Definitions

• the invention relates to an external gear pump with at least two meshing with each other in an engagement region gears and a bypass piston, the construction of a Drucka driven external gear pump to the effect erm allows an excess flow through a bypass from a pressure side to a suction side of the driven external gear pump passes.
• the object of the invention is to extend the life of an external gear pump according to the preamble of claim 1.
• the task is in an external gear pump with at least two meshing with each other in an engaging portion gears and a bypass piston, the pressure built up a Drucka the externalmitteniereradpum PE to the effect erm allows that an excess flow through a bypass from a pressure side to a suction side of the driven external gear pump passes dadu rch solved that the bypass piston is arranged with closed bypass with a small clearance to the meshing with each other in the meshing gears.
• the external gear pump is preferably mechanically driven.
• a drive shaft is used, which is mechanically coupled to an internal combustion engine. High open back pressures and the associated losses can be avoided via the opened bypass, especially if the pumped medium of the external gear pump is cold and tough.
• the external gear pump is characterized in that the bypass piston has an outer diameter which is significantly smaller than the outer diameter of the meshing gears. This ensures that an axial contact surface for the gears, for example on a housing of the external gear pump, is not so much reduced by the bypass piston, as for example in the known from the German patent application DE 44 36 518 A1 Zahnradpum PE.
• Another preferred embodiment of the originally designed is characterized in that the bypass piston is supported with a closed bypass on a housing paragraph.
• the housing paragraph may be provided in a pot-like housing base or in a lid of the housing.
• Another preferred embodiment of the strictly leopardradpum PE is characterized in that the bypass piston is hydraulically biased against the Genzousea bsatz.
• the hydraulic bias ensures that the bypass piston rests against the housing shoulder when the bypass is closed.
• the hydraulic bias can be generated by a hydraulic pressure acting on the bypass piston. When the hydraulic pressure is reduced, and / or when the discharge pressure of the external gear pump becomes larger than the hydraulic bias in the engaging portion of the meshing gears, the bypass piston moves away from the housing shoulder and releases the by-pass.
• a further preferred embodiment of the external gear pump is characterized in that the bypass piston is biased by a spring against the housing shoulder.
• the spring is preferably a pressure spring, by means of which the bypass piston is held in contact with the housing shoulder when the bypass is closed.
• the bypass piston may additionally be subjected to a hydraulic pressure in order to improve the activation of the hydraulic piston. fibers.
• the spring can be used to represent a pressure relief valve together with the bypass piston. If, for example, the delivery pressure of the external gear pump is then fed back to the bypass piston as a control force via a differential surface on the bypass piston, the function of a differential pressure valve can also be represented with the bypass piston.
• bypass piston it is possible to at least partially make the bypass piston out of a material having a shape or shape memory capability, that is, a so-called shape memory alloy. It can thereby be achieved that the bypass piston changes its shape, in particular its size, as a function of the temperature. This effect can be used to control the bypass.
• a material having a shape or shape memory capability that is, a so-called shape memory alloy.
• the bypass piston changes its shape, in particular its size, as a function of the temperature.
• This effect can be used to control the bypass.
• other temperature-dependent components can be used which provide a control force and / or a control path.
• the control force on the bypass piston can also be applied mechanically, electrically or by another technical height.
• a further preferred embodiment of the external gear pump is characterized in that the bypass piston has an axial guide portion, with which the bypass piston in a housing Ausne is guided reciprocally movable back and forth.
• the housing recess may be arranged in a pot-like housing base body or in a cover of the housing.
• a further preferred embodiment of the external gear pump is characterized in that the bypass piston has an axial bypass section which has a smaller outer diameter than the guide section and at the free end of which a bypass closing surface is formed.
• the bypass closing surface is, for example, circular and with a closed bypass with little play to the meshing with each other in the engagement region gears arranged.
• a further preferred embodiment of the external gear pump is characterized in that the guide section has a greater axial extent than the bypass section. As a result, the guidance of the bypass piston in the housing recess is improved.
• a further preferred embodiment of the external gear pump is characterized in that the bypass piston between the guide section and the bypass section has a step, with which the bypass piston with closed bypass on the GE. housing paragraph strikes. Via the axial extent of the bypass section, the play between the bypass closing surface and the gears meshing with one another in the engagement region can be adjusted.
• the invention furthermore relates to the use of a previously described external gear pump for supplying a hydraulic control, in particular an automatic transmission of a motor vehicle.
• the hydraulic controls in A utomatic gearboxes supply the gearbox actuators and, on the other hand, are often required for cooling and lubrication functions.
• the external gear wheel pump according to the invention an advantageous alternative to a mechanical decoupling of the Pum pe is provided by its mechanical drive.
• the outside gear wheel pump can be short-circuited as required depending on the bypass enabled by the bypass piston in order to minimize pressure losses of the driven pump. As a result, the promotion of the external gear pump is interrupted.
• Figure 1 shows an external gear pump according to the invention in longitudinal section with a closed bypass
• Figure 2 shows the external gear pump of Figure 1 with open bypass
• Figure 3 shows a similar embodiment as in Figures 1 and 2 m with a biased by a spring bypass piston in its closed position.
• FIGs 1 and 2 ei ne external gear pump 1 with a pump housing 2 in longitudinal section with open and closed bypass dargestel lt.
• the pump housing 2 comprises a pot-like housing basic body, the bottom of a P latte 3 is amplified.
• the cup-shaped main body of Pum pengeophuses 2 is closed by a pump cover 4.
• gears 11, 12 mesh with each other.
• the gear 1 1 is driven by a drive shaft 14 (not illustrated) of a driver 15.
• the gear 12 is rotatably mounted on a pillow block 18 in the Pümpengephaseuse 2.
• In one Engagement region 20 meshes the two gears 11, 12 so that a conveying medium is conveyed by means of the two gears 11, 12 from a suction side to a pressure side of the external gear pump 1, as long as the gear 11 is driven via the drive shaft 14 ,
• the pump housing 2 has in the engagement portion 20 of the two gear wheels 11, 12 a housing recess 24 in which a bypass piston 25 is guided reciprocally movable.
• the bypass piston 25 defines with its end face remote from the engagement region 20 a control pressure chamber 26, which can be acted upon by hydraulic pressure.
• the bypass piston 25 is biased via the control pressure chamber 26 hydraulically against a housing shoulder 30, which is formed in the casement securement 24.
• the bypass piston 25 is in the axial direction in an axial guide portion 31 and an axial By passportion 32 divided.
• the axi al guide portion 31 has a larger outer diameter than the axial bypass portion 32.
• a step 33 is formed with which the bypass piston 25 abuts in its closed position shown in Figure 1 on the housing shoulder 30 or abuts.
• the bypass piston 25 has a bypass closing surface 35, which in the closed position of the bypass piston 25 is arranged with a small clearance, which is not visible in FIG.
• an external gear pump 41 is shown, which is similar to the external gear pump 1 of Figures 1 and 2 se hr. Identical parts are provided with the same reference numerals. To avoid repetition, only the differences between the two external gear pumps 1 and 41 will be discussed below.
• the bypass piston 45 is biased by a spring 46 in its closed position.
• the spring 46 is executed as a helical compression spring and partially received in a corresponding recess of the bypass piston 45.
• the bypass piston 45 can be additionally hydraulically actuated via the control pressure.

Priority Applications (2)

Applications Claiming Priority (2)

Publications (2)

Family

ID=44629786

Family Applications (1)

Country Status (3)

Cited By (1)

Citations (1)

Family Cites Families (6)

• 2011
  • 2011-05-23 DE DE112011102000T patent/DE112011102000A5/de not_active Ceased
  • 2011-05-23 CN CN201180029288.XA patent/CN103026068B/zh not_active Expired - Fee Related
  • 2011-05-23 DE DE201110102259 patent/DE102011102259A1/de not_active Withdrawn
  • 2011-05-23 WO PCT/DE2011/001099 patent/WO2012016552A2/de active Application Filing

Patent Citations (1)

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